JP2538066B2 - Particle management board manufacturing method and particle management method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a particle management substrate and a particle management method.

2. Description of the Related Art A defect inspection apparatus injects a laser beam onto a substrate with dust, detects scattered light scattered by the dust, and determines the presence or absence of dust from the intensity of the detected light.

However, this method does not detect dust with a minimum particle size of 0.17 μm or less. Therefore, it is necessary to increase the output of the laser, but the noise increases according to the output, the S / N ratio is not improved, and the price increases by one digit or more. In order to solve this, a method has been proposed in which a foreign substance on the substrate can be measured with high sensitivity by covering the substrate surface with a substance having a light reflectance higher than that of silicon (Japanese Patent Laid-Open No. 62-91842). .

On the other hand, in the case of a substrate with a high light reflectance, the ratio of the incident light intensity to the reflected light intensity is high, that is, the S / N ratio is poor, and it is difficult to determine the presence or absence of particles on the substrate. It has been proposed to form a temporary reflection film thinly by spin coating (Japanese Patent Laid-Open No. 62-66139).

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As described above, in such a configuration of the related art, when a film having high reflectance is grown on a substrate, unevenness on the substrate surface due to a difference in particle size of the formed film itself is detected. And the growth of the film blurs the outer contour of the dust, which reduces the reliability of the scattered light detected.

In the case of film growth by spin coating, spin coating generally acts as a dust source in many cases, and the reliability of scattered light to be detected decreases because the outer contours of the substrate and dust are swollen due to film formation.

Both methods cannot measure the amount of dust generated during film growth in each device. Further, since the scattered light due to the unevenness of the substrate is also detected, it is difficult to distinguish whether the signal is inherent to the substrate or the original signal of dust.

It is an object of the present invention to provide a method for manufacturing a particle management substrate and a particle management method which can solve the above-mentioned problems and can be used in a highly accurate particle inspection in a wide range of steps.

Means for Solving the Problems The present invention, in order to solve the above problems, after forming a thin glass film capable of heat flow on a substrate containing surface particles,
The thin glass film is annealed and heat-flowed.

Further, after forming a heat-flowable glass film on a substrate containing surface particles, the glass film is annealed and heat-flowed, and the substrate is irradiated with light having a specific wavelength to detect scattered light from the substrate.

Action In the present invention, a film that flows by heat treatment is formed on the substrate surface, the film that covers dust and particles by the flow does not blur the outer contours of dust and particles, and irregular irregularities on the substrate surface are flattened, Further, it can be used in all the steps capable of forming a film, and further, dust and particles generated during the film formation can be measured.

Example A method for producing a measurement substrate according to the present invention will be described in detail with reference to FIG.

Reference numeral 1 is a silicon substrate having a plane orientation (100) and 6 inches, 2 is boron-phospho-silicate glass, 3 is dust and particles, and 4 is a surface contour of dust and particles.

A boron-phosphosilicate glass (hereinafter referred to as BPSG) film 2 is grown on a silicon substrate 1 by atmospheric pressure CVD (FIG. 1 (a)).

The silicon substrate 1 used in FIG. 1 uses a substrate on which a plurality of dusts and particles 3 having different sizes are placed.

The BPSG film 2 is deposited by, for example, atmospheric pressure CVD using 5% diborane (B ₂ ) diluted with monosilane (SiH ₄ ) and argon as a gas species.
H ₆₎ and argon diluted 5% phosphine (PH _3),
Oxygen (O ₂ ) mixed gas, gas flow rate SiH ₄ = 100sccm, B ₂ H ₆
＝ 10sccm, PH ₃ ＝ 10sccm, O ₂ ＝ 20sccm, growth temperature 400 ℃,
The growth time was 6 minutes. At this time, the film thickness of the BPSG film 2 is about 30.
I used 00Å.

Next, the silicon substrate 1 on which the BPSG film 2 is deposited is annealed in a normal pressure furnace (FIG. 1 (b)).

The annealing conditions at this time are, for example, an annealing temperature of 950 ° C. and an annealing time of 70 minutes in a nitrogen atmosphere.

At this time, the composition of the BPSG film 2 is B ₂ O ₃ = 5 wt% and P ₂ O ₅ = 8.
% By weight and SiO ₂ = 87% by weight are used.

In the result of measuring the number of particles after the treatment shown in FIG. 1A, it is observed that dust is distributed in a striped pattern on the substrate surface.

For this reason, as shown in FIG. 1A, the BPSG film 2 deposited on the dusts and particles 3 is gently deposited on the surface contours 4 of the dusts and particles 3, so that the surface contours of the dusts and particles 3 are formed. The boundary of No. 4 is not clear and malfunctions. Further, the grains of the BPSG film 2 form large grain boundaries immediately after growth, and irregularities caused by macroscopically non-uniform BPSG grain diameters are detected. The unevenness caused by uneven particle size is about 0.3 μm to 0.03 μm
m.

This will be explained from the principle of the surface defect inspection apparatus used in the embodiment.

FIG. 2 shows a conceptual diagram for explaining the surface defect inspection apparatus.

11 is a light source, 12 is a detector, 13 is a measurement board, and 14 is a light source.
Incident light emitted from 11 and entering the substrate, 15 is reflected light reflected on the measurement substrate 13, and 16 is scattered light scattered on the measurement substrate 13.

As the light source 11, He-Ne laser light (wavelength 633 nm) was used. Incident light 14 emitted from the light source 11 is incident on the measurement substrate 13 at an incident angle θ.

The incident angle is indicated by the inclination angle from the plane perpendicular to the measurement substrate 13. The incident light 14 is incident on the surface of the measurement substrate 13 symmetrically with respect to the incident plane.
Scattering occurs due to the reflected light 15 reflected by and the defects on the surface of the measurement substrate 13 to become scattered light 16. This scattered light 16 is detected by the detector 12 to determine the presence or absence of a defect.

Furthermore, FIG. 3 shows a schematic diagram for explaining the types of defects that cause light scattering. In FIG. 3, λ indicates a wavelength and n indicates an integer.

21 in FIG. 3 is a defect larger than the wavelength of light, such as scratches, cracks, epis, spikes, slip lines,
It is called a stacking fault.

22 in FIG. 3 is a defect smaller than the wavelength of light and is an isolated particle.

Reference numeral 23 in FIG. 3 is much smaller than the wavelength of light, and is irregularity or fine particles on the substrate surface, but it extends over a wide range on the substrate surface.

Here, when it is desired to measure dust or particles existing on or inside the substrate or the growth film as in the present invention, it corresponds to measuring a large defect 21 and a small defect 22, the fine particles 23 are noise. Be observed as.

That is, the scattering by the fine particles 23 causes the detector 12 to generate a slowly changing DC electrical component (noise).

By this method, dust and particles existing on or in the substrate, the grown film, or the inside of the film can be reliably measured.

As a reason for this, as shown in FIG. 1B, the BPSG film 2 deposited on the dust and particles 9 was gently deposited on the surface contour portion 4 of the dust and particles 3. The film is flowed to clarify the boundary of the surface contour portion 4 of the dust and particles 3, and the grain boundaries in which the particles of the BPSG film 2 are formed large immediately after the growth are eliminated by the annealing treatment.
This is because the unevenness caused by the BPSG particles has disappeared.

This state was divided so that the cross section of the silicon substrate was exposed, and the cross section was examined with a scanning electron microscope.
It was confirmed that the shape was as shown in. From this, it is understood that the unevenness generated on the substrate by the flow of the BPSG film is filled and flattened. Note that although the BPSG film is used here, the flow may occur at a practical annealing temperature. Any material can be used, for example, boron silicate glass (BSG) containing boron, phospho silicate glass (PSG) containing phosphorus, arsenic silicate glass containing arsenic, or a thermal oxide film. Any material whose temperature does not exceed the melting point of silicon can be used.

Further, although the growth apparatus was carried out by atmospheric pressure CVD, since the present invention is used to measure the dust and particles existing on or inside the substrate or the growth film, the growth of particles and dust of the film growth apparatus Since the occurrence can be investigated, the type of growth apparatus does not matter.

The film composition of the BPSG film of this example is B ₂ O ₃ = 5% by weight,
Although P ₂ O ₅ = 8 wt% and SiO ₂ = 87 wt% are used, this is a value suitable for performing the BPSG film flow at a low temperature of 1000 ° C. to 900 ° C. I will get it.

Although He-Ne light is used as the light source of the defect inspection apparatus in this embodiment, any high-intensity parallel light beam can be used, such as ultraviolet light.

The growth film thickness used here is 3000 Å because it was used to make it easier to observe the flow shape of the BPSG film after annealing. However, the number of defects is displayed as a value including those contained in the film. However, if the film thickness is made too thick, the throughput will be poor for use as a monitor for defect inspection, so about 0.1 μm to 1 μm is practically preferable.

Although silicon is used as the measurement substrate in this embodiment, any substrate can be used as long as it can deposit a film and does not cause distortion such as thermal deformation due to annealing. It is a glass substrate such as a quartz substrate or a low expansion glass substrate, a GaAs substrate, an InP substrate. There are compound substrates such as substrates and semiconductor substrates such as Ge substrates.

Effects of the Invention According to the present invention, the amount of dust and the amount of particles generated during film growth in the actual film forming step can be managed, and further, the intensity of scattered light due to dust and particles is not reduced,
Since false scattered light due to irregular irregularities on the substrate surface is not detected, highly reliable dust and particle management is possible.

[Brief description of drawings]

1 (a) and 1 (b) are cross-sectional process diagrams showing a method for manufacturing a particle management substrate of the present invention, FIG. 2 is a conceptual diagram for explaining a surface defect inspection apparatus, and FIG. 3 is a defect that causes light scattering. It is a figure explaining. 1 ... Recon substrate, 2 ... Boron / phospho / silicate glass, 3 ... Dust and particles, 4 ... Dust and particle surface contours.

Claims (3)

(57) [Claims] 1. A method for manufacturing a substrate for particle management, which comprises forming a thin glass film capable of heat flow on a substrate containing surface particles and then annealing the thin glass film for heat flow. 2. A substrate installed in a glass film forming apparatus for heat-flowing for particle management, and a heat-flowable glass film formed on the substrate by the glass-film forming apparatus to an arbitrary thickness. A method for manufacturing a substrate for particle management, which comprises: 3. A glass film capable of heat-flowing is formed on a substrate containing surface particles, and the substrate having the glass film annealed and heat-flowed is irradiated with light of a specific wavelength to detect scattered light from the substrate. A particle management method characterized by: